Talaromyces albisclerotius 2020

Talaromyces albisclerotius B.D. Sun, A.J. Chen, Houbraken & Samson 2020

MycoBank No: 833135 

Holotype: China, Xinjiang, soil, 2002, isolated by L. Cai, Holotype CBS H-22837, culture ex-holotype CBS 141839 = DTO 340-G5.

Morphological description

Colony diam, 7 d (mm). CYA 5–8; CYA 30 °C 3–4; CYA 37 °C No growth; MEA 19–20; MEA 30 °C 8–9; OA 13–14; YES 6–7; CREA No growth; CYAS No growth; DG18 5–6.

Colony characters. CYA 25 °C, 7 d: Colonies moderately deep, slight sulcate; margins entire; mycelium white; texture floccose; sporulation dense; conidia en masse greyish yellow-green (68); soluble pigments absent; exudates absent; reverse buff (45). MEA 25 °C, 7 d: Colonies moderately deep, sulcate; margins entire; mycelium white and primrose (66); texture floccose; sporulation dense; conidia en masse pistachio green (92); soluble pigments absent; exudates absent; reverse ochreous (44). YES 25 °C, 7 d: Colonies moderately deep, plane; margins entire; mycelium white; texture floccose; sporulation moderately dense; conidia en masse pistachio green (92); soluble pigments absent; exudates absent; reverse buff (45). DG18 25 °C, 7 d: Colonies moderately deep, plane; margins entire; mycelium sulphur yellow (15); texture floccose; sporulation sparse; conidia en masse greyish yellow-green (68); soluble pigments absent; exudates absent; reverse sulphur yellow (15). OA 25 °C, 7 d: Colonies moderately deep, plane; margins entire; mycelium white and primrose (66); texture velvety; sporulation dense; conidia en masse yellow green (71); soluble pigments absent; exudates clear droplets; reverse greyish yellow-green (68). CREA 25 °C, 7 d: No growth.

Micromorphology. Conidiophores biverticillate, with a minor proportion having subterminal branches; stipes smooth, 70–130 × 3–4 μm, extra branches 10–20 μm; metulae 3–5, divergent, 8.5–11 × 4–4.5 μm; phialides 4–6, acerose, 9–11 × 3–5 μm; conidia smooth, subglobose to fusiform, 2–4.5× 3–4 μm. Ascomata not observed, white sclerotia present on OA after 1 wk.

Habitat: soil.

Distribution: China.

GenBank Accession: ITS:MN864276; BenA:MN863345;CaM:MN863322; RPB2 :MN863334.

Notes: Talaromyces albisclerotius is characterized by the production of white sclerotia on OA after 1 wk incubation; these sclerotia remain sterile and no ascospores are observed after prolonged incubation up to eight wk. Talaromyces assiutensis and T. trachyspermus could produce white ascomata, but their ascomata mature after weeks and release ascospores (Yilmaz et al. 2014). Phylogenetically, T. albisclerotius clusters with T. diversus and T. brasiliensis, but T. diversus grows faster on MEA, and T. brasiliensis produces rough conidia (Yilmaz et al. 2014; Barbosa et al. 2018). 

Reference: Sun B-D, Chen AJ, Houbraken J (2020) New section and species in Talaromyces. MycoKeys 68: 75–113. https://doi.org/10.3897/mycokeys.68.52092

Talaromyces albisclerotius CBS 141839^T a colonies from left to right (top row) CYA, MEA, YES and OA; (bottom row) CYA reverse, MEA reverse, DG 18 and CREA b sclerotia on OA after two weeks c–g conidiophores and conidia. Scale bars: 1000 μm (b), 10 μm (c–g).